Hi,
My next door neibhour is having his kitchen remodled. Part of the remodle involved tearing up some of the floor. A couple of large areas did have black mold under them and the wood had actually delaminated. Anyhow to cut a long story short, it seems that a couple of areas in the slab refuse to completelty dry out, so the floor guy won’t go ahead and replace the floor until the slab completly dries out. He’s freaked my neighbour out by suggesting he probably has a leak somewhere under the slab ($$$$$$)I checked the water meter and it shows no running water flow. Could it be a leaky drain? He’s got some guy coming out on Thurs to run some test. Anybody know what these test are?
Mike
Replies
Leaks under a slab are unfortunately not uncommon. It happens when either the water supply or the fill surrounding the pipe is corrosive and the copper pipe corrodes through, or occasionally its due to stresses on the pipe, damage during construction, etc. One leak isn't that big a deal -- a PITA but at least in this case the floor is already up so cutting it open to fix it isn't that painful. But one leak usually signals that more are to come, and they aren't all likely to be conveniently located.
In FL it's reasonable to run the water lines overhead (using PEX, if code allows), and that's maybe what should be done. The question is whether to replumb the entire house all at once (assuming more pipes will fail) or just do it a little at a time as the pipes go bad.
The Water Meter Might Not Show a Slow Leak.
If the leak is slow enough it won't really show on a water meter.
In a humid climate, with a slow draining soil, it won't take much of a leak to cause a wet spot.
As others have said, it may be easiest, and less costly, to reroute the lines through the attic. Particularly, if the house is a single story.
>>>I checked the water meter
>>>I checked the water meter and it shows no running water flow. Could it be a leaky drain?
Does the water meter have a trickle indicator? Something like this:
http://www.jerman.com/reading_dlj.html
If so, then it may not be a leak. Have you considered surface run-off? Does the house have proper perimeter drainage around the footings?
Wow, we're re-piping the house
but we don't know if there's a leak yet. A good plumber should be able to pressure-test most or all of the piping fairly easily, and determine if and probably where a leak is, if any. There are also leak detection companies that specialize in finding these problems. If there is a bigger problem, such as piping that is guaranteed to eventually rot out because of soil type, water quality, or being encased in concrete, then complete re-piping might be wise and a local plumber can advise on that as well. And as mentioned above, someone needs to determine whether roof water or surface water is causing the problem. The floor guy is probably right to refuse installing over a damp slab, but I wouldn't automatically assume there's a leak.
high water table?
i have an area like that in my basement and after several discussions with neighbours i have found that our area has a high water table. some of my neighbours have 3 sump pumps in their basements just to keep up with it
Thanks all. He's getting a leak guy out there tomorrow. I'm intrested as to how they detect the leak myself. I'll post an update. I'm thinking it's the water table.
Mike
Well, first thing they can do is determine if there's a copper pipe running under there -- fairly easy to trace the pipes through the floor. Not sure how they'd detect a leak, but I'm sure they have ways.
Thanks
I've just come back from next door. The professional did a pressure test, that did fine so no water leak. The concensous was that it maybe a failed or non existant vapour barrier under the slab, allowing moisture to wick up. I guess he's going to have to seal the slab.
Mike
how or what material would you use to seal that slab? do you mean styrofoam? plastic? is there someting else that could/should go down first?
First off I''m no expert but on a home they built near by I did see the workers lay down a material like a waterbed liner.
Mike
http://www.architects.org/emplibrary/UnderSlabVaporBarrierPPP.pdf
As someone mentioned - proper drainage away from the house is a likely issue and should be the first remedial action taken.
Downspouts should extend 6-10' away from the house and soil should slope away from the house for the same distance.
crystalline
i think their is a material you spray on the concrete, it crystallizes in the concrete, fills the voids and becomes impermeable, cant think of what its called exactly tho